Incandescent lamp and similar device



May 2, 1933. c. SEVERIN 1,906,319

YINCANDESCENT LAMP AND SIMILAR DEVICE Filed Aug. 23, 1928 2 Sheets-Sheet 1 M rna-'03. Clnfl: 5232;273:132,

.Hfrs Ar 1022x7235 .May 2, 1933. c. SEVERIN INCANDESCENT LAMP AND SIMILAR DEVICE Filed Aug. 23, 1928 I 2 Sheets-Sheet 2 185-5 WW,- WW

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Patented May 2, 1933 PATENT OFFICE CARL SEVEBIN,

OF CLEVELAND HEIGHTS, OHIO, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A. CORPORATION OF NEW YORK INCANDESCENT LAMP AND SIMILAR DEVICE Application filed August 23, 1928. Serial No. 301,583.

My invention relates to incandescent electric lamps and similar devices and more particularly to arrangements of filaments in multiple filament lamps and to the so-called mounts which comprise not only the filaments and their wire supports, but also the glass stem with which is usually incorporated an exhaust tube. The current is supplied to the filament by leading-in wires, portions of which are sealed in the glass stem, the inner portion of the so-called leads being stiff enough to serve as supports as well as conductors. One feature of my invention is that the leads, especially at the sealed-in portlon are effectively insulated from each other which avoids short circuiting, and the arrangement is such that bending of the inner leads is avoided and, as a result, the press or sealed portion of the glass stem which is clamped around the leading-in conductors is practically not subjected to strain. Another feature of my invention is that the filaments are supported in a very effective way from an illumination standpoint and also from the standpoint of ruggedness of construction. Further features and advantages of my invention will appear from the following description of a species thereof and from the accompanying drawings.

In the drawings Fig. 1 is a fragmentary elevation on an enlarged scale of a lamp stem made according to my invention; Fig. 2 is a horizontal section along the line 2-2 of Fig. 1; Fig. 3 is a fragmentary elevation of a pair of stem clamping jaws; Fig. 4 is an enlarged plan view of'the clamping jaws; Fig. 5 is an elevation of a completed lamp comprising my invention; Fig. 6 is an elevation at right angles thereto; Fig. 7 is an elevation of a modification of the lamp shown in Fig. 5; Fig. 8 is a fragmentary perspective on an enlarged scale of the mount forming part of the lamp shown in Fig. 5; Fig. 9 is a similar view of the mount forming art of the lamp shown in Fig. 7; Fig. 10 1s a bottom plan view of the lamp base; Fig. 11 is a wiring diagram of the lamp shown in Fig. 5; and Fig. 12 is an elevation of the lam its socket and associated reflector.

rig invention is applicable to various types of multiple filament lamps but is shown in the drawings as applied to miniature lamps such as are used in connection with vehicle headlights. As shown in Figs. 1 and 2, the lamp stem may be of the tipless type such as disclosed in the Mitchell and White Patent 1,423,956 issued July 25, 1922, and comprises a flare tube 10 and an exhaust tube 11. These parts together with a plurality of leading-in conductors 12 and 12 are assembled on an automatic stem machine such as disclosed in the Fagan and Staudenmeir Patent 1,655,141 issued January 3, 1928. The assembly is then carried by a series of fires which fuse the lower end of the stem thereby forming a solid mass of glass uniting the exhaust tube to the flare tube. A pair of clamping jaws (Fig. 3) located in the path of travel of the stem assembly are adapted to then press the fused glass so as to seal the leadingin conductors at this portion.

During assembling, the leading-in conductors are arranged in the flare tube so that in a horizontal section they appear as the four corners of a quadrilateral preferably approaching a square and are all substantially equally spaced from and parallel with the axis of the lamp stem as shown in Fig. 2. By recessing the clamping jaws 13 and 14, as shown in Fig. 4, the fused glass may be ressed around the said leading-in conductors without disturbing their relative arrangement. The aperture 15 which communicates with the exhaust tube 11 is definitely positioned by the method disclosed in the Phelps and Raus Patent 1,659,613, February 21, 1928, by means of a lug 16 extending from the jaw 14.

In Figs. 5 to 9 inclusive are shown two forms of multiple filament lamps made according to my invention, each of which comprise three separate filaments. In the form shown in Figs. 5. 6, and 8, the lamp comprises the usual bulb 17, base 18 and my improved stem 19. Filaments 20 and 21 are of high candle power and preferably of coiled tungsten wire. The filament 20 is carried by two of the conductor supports 12 and 12 extending from the stem 19 while the filament 21 is carried by another of the said supports 12 and an auxiliary su port 21' which is electrically and mechanics y connected to the conductor support 12'. These filaments are located on opposite sides of the ax1s of the lamp and equally spaced therefrom and lie in planes substantially parallel with each other. The filament 22 is a low candle powered filament which gives a reduced lilght, such as used for parking purposes as istinguished from the driving li hts which are furnished by either of the ot er filaments. The filament 22 is located in the rear of the filament but lies in substantially the same plane therewith. This novel mounting of the filament 22 is an important feature from a manufacturing as well as a quality standpoint. It is comparatively simple to mount and should it buckle or become detached from either of its supports during operation of the lamp, no serious damage wil result, due to its isolated position with reference to the other conductor supports. As shown in Figs. 8 and 11, the filament 22 is connected in series with the filament 20 making it inoperative upon the failure of the filament 20. n the form shown in Figs. 7 and 9 the filament 22 is mounted so as not to be dependent upon the condition of the filament 20 for its operation.

Three of the conductors 12 supply current to the various filaments and these are connected to the base contacts 23, 24, and 25 (Fig. 10), while the conductor indicated as 12' being the common return wire, is connected to the shell of the base 18. These conductors are substantially unidirectional and are substantially equally spaced throughout their extent.

In Fi 11 the electrical connections for the form 0 lamp shown in Fi s. 5, 6 and 8 are shown diagrammatically. Iieading from the terminal of the battery 27 is conductor 28 connected to switch 29 around which are disposed the switch contacts 30, 31, 32, 33 and 34. A conductor 35 extends from contact 31 to one of the high candle power filaments 20 and from thence to ground 36 through the common conductor 12'. The conductor 37 extends from the contact 32 to the other high candle power filament 21 and back to ground 36 through the common conductor 12'. Conj ductor 38 extends from the contact 30 to the low candle power filament 22, which, as shown, is connected in series with the filament 20, the current being directed throu h the filament 20 back to ground by way of t e common conductor 12'. Conductor 39 connects the contact 33 to the conductor 37 and the conductor 40 connects the contact 34 to the conductor 35. When the switch 29 enges contact 31, as shown, the filament 20 is i luminated; when it engages contact 32 the filament 21 is illuminated; when it engages contact 30 the parking filament 22 is illuminated; and when it is rotated so as to engage the contacts 33 and 34, both high candle power filaments 20 and 21 are illuminated in paral- For simplicit of manufacture, the driving filaments 20 an 21 have been placed as shown on op osite sides of the axis AA of the lamp ut in use with a parabolic reflector 41, such as shown in Fig. 12, it is desirable that the filament 21 be located along the principal axis and at the focus of the said reflector and the filaments 20 and 22 above it. This is accomplished by slightly oifsettin the lamp socket 42 from the axis B-B of t e reflector so that when the lamp is inserted therein the result is secured. In order that this arrangement of filaments with relation to the reflector may be automatically secured I rovide on the lamp base 18 three pins 43 (Fig. 10) unequally s aced from each other. These pins are cause to register with three slots (not shown) formed in the lamp socket. This arrangement prevents improper insertion of the lamp in its socket.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an electric incandescent lamp comprising a glass stem, a bulb and a base, the combination of a plurality of filaments mounted within said bulb and at least three leading-in conductors sealed in said stem and electrically connected to said filaments, said stem comprising a seal portion having lobes each surrounding a leading-in conductor, and an exhaust tube extending within said stem and integrally connected with said seal ortion, the latter having an aperture exten ing therefrom between a pair of said lobes and communicating with said exhaust tube.

2. In an electric incandescent lamp or similar device comprising a glass stem, a bulb and a base, the combination of a pluralit of elements mounted within said bulb an at least three leading-in conductors sealed in said stem and electrically connected to said elements, said stem comprising a seal portion having lobes each surrounding a leadin -in conductor and an exhaust tube extend in within said stem and inte rally connecte with said seal portion, the latter having an aperture extending therefrom between a pair 0 said lobes and communicating with said exhaust tube.

In witness whereof, I have hereunto set my hand this 21st day of Au ust 1928.

CA L SEVERIN. 

